Police Appeal for Severe Disruption

The Hong Kong Police sent a text message to my phone (and probably many people's phones) this morning:

So, what is the message? It is a appeal, that is a serious, urgent, or heartfelt request. What do the Police want? They want a Public Event on Hong Kong Island this afternoon. They also give permission for causing severe disruptions. While we are participating in this severely disruptive public event, we should stay alert and check for Police updates, this is generally good advice. Finally, we should not reply... to who? Perhaps the Police? So, while causing severe disruptions, should a Police officer give you an update on the situation, you should, on no account, reply to the officer.

This clearly shows the dangers of using ambiguous words in messages, especially when they are short and therefore lacking fuller context.